Blasting cap



Patented Jan. 15, 1924.

UNHTE ERNEST M. SYMMES, OF WILMINGTON, DELAWARE, ASSIGNOR TO HERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

BLASTING CAP.

No Drawing.

T 0 all whom it may concern:

Be it known that I, ERNEST M. SYMMEs, a citizen of the United States, residing at Wilmington, county of New Castle and State of Delaware, have invented a new and useful Improvement in Blasting Caps, of which the following is a full, clear, and exact description. I

My invention relates to an improvement in blasting caps or primers and more particularly to an improved charge therefor.

Heretofore, in the manufacture of blasting caps or primers, it has been customary to use, as a charge, fulminate of mercury, either alone or mixed with chlorate of potash, trinitrotoluol (TNT), picric acid, tetryl, azides of the heavy metals, etc. These,wh1le fulfilling the requirements for a charge for blasting caps or primers are either extremely dangerous to manufacture and handle, such as mercury fulminate, lead azide, and tetryl, or are of insufficient detonating power when used in quantities permissible in the usual size of blasting cap to perfectly detonate a charge of commercial explosives, as is the case with picric acid or TNT.

Many attempts have been made to provide a substitute for the above compounds which will be as etfective or more so, and at the same time which will be relatively safe to manufacture and handle. Such attempts have been, however, not entirely satisfactory, since increased safety is usually accompanied by decreased efficiency.

Now the object of my invention is to provide a charge for blasting caps or primers which will be of great efficiency and at the same time relatively safe, enabling its safe manufacture and loading into the cap or primer.

To this end, I have discovered that trihitrobenzol having the chemical composition H (No fulfills all the desiderata to a superior degree.

In accordance with my invention, trinitrobenzol may be used alone or in admixture with (a) an oxidizing agent, (6) some ex- Serial No. 583,362.

plosive of relatively easy ignition, or (a) some other brisante explosive.

As an example of an oxidizing agent I may mention chlorate of potash, while an.

easily ignited explosive which will fulfill the requirements might be, for example diplumbicditrinitroresorcinol, sometimes called styphnic acid or briefly T. N. R; while tetranitroanilin, tetryl (socalled) lead azide and mercury fulminate are examples of brisante explosives which may be used.

The charge of a blasting cap or primer may, on one hand for example, be composed of trinitrobenzol or a mixture of trinitroben- 201 with chlorate of potash, tetranitroanilin, diplumbicditrinitrosorcinol, tetryl, lead azide or fulminate of mercury. On the other hand, for example, there may be a main charge or base charge so-called of trinitrobenzol upon which is superimposed a primer charge of a thin layer of fulminate alone, fulminate-chlorate of potash mixture, or of lead azide-diplumbicditrinitroresorcinol.

It will be appreciated that the above variations in the application of my invention are' merely illustrative.

My invention is applicable to blasting caps of all kinds as for example, open and closed types which are set off by fuse and a current of electricity respectively, and to primers generally, and I have found that both from calculations and practical tests that the energy developed by trinitrobenzol is higher than any other known brisante explosive, while at the same time it is relatively safe.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

A blasting cap or primer, for detonating explosives, including a charge of trinitrobenzol.

In testimony of which invention, I have hereunto set my hand, at Wilmington, on this 18th day of August, 1922.

ERNEST M. SYMMES. 

